Fuel supply systems

ABSTRACT

A fuel supply nozzle for a gas turbine engine comprising a porous element pierced by a number of passages through which air may pass into the combustion chamber, drawing in fuel which is fed into the porous element.

United States Patent Ware [451 Sept. 19, 1972 [5 FUEL SUPPLY SYSTEMS[56] References Cited [72] Inventor: Peter G. Ware, Rugby, EnglandUNITED STATES PATENTS [73] Assignee: The Dunlop Company Ltd., London,2,227,899 l/ l94l Grubb ..43 1/328 England 2,510,645 6/ l 950 McMahan..60/39.65 2,828,609 '4/1958 Ogilvie ..60/39.74 R [221 July 2,918,11812/1959 Schirmer ..431/328 [211 AppL 53,212 2,922,279 l/ 1960 Roberson..60/39.74 R 3,085,394 4/1963 Handley ..60/39.74 A

[] Foreign Application Priority Data Primary Examiner-Douglas Hart July11, 1969 Great Britain ..3494l/69 Mama-Stevens Msher [57] ABSTRACT [52]US. Cl ..60/39.74 R, 239/145, 431/328 [51] Int. Cl. ..F02c 3/24 fuelSupply nozzle a gas turbme engme compns' 581 Field of Search ..60/39.7439.72 R, 39.65, mg a element named by a umber passages through which airmay pass into the combustion chamber, drawing in fuel which is fed intothe porous element.

7 Claims, 1 Drawing Figure FUEL SUPPLY SYSTEMS This invention relates tofuel supply systems and particularly to systems for the supply of fuelto gas turbine engines.

One object of the invention is to provide an improved fuel supply nozzlefor a gas turbine engine.

According to the invention a nozzle for supplying liquid or gaseous fuelto the combustion chamber of a gas turbine engine comprises an elementformed from a porous material through which the fuel may flow, theelement having a plurality of passages formed therethrough for thesupply of air.

According to the invention also, a gas turbine engine incorporates afuel supply nozzle comprising an element of porous material throughwhich the fuel is arranged to flow, the element having a plurality ofpassages formed therethrough and arranged to be connected to a source ofair pressure, the arrangement being such that a flow of air through thepassages will carry the fuel into a combustion chamber.

The porous material may be a porous metallic material of the kind whichis in the form of a threedimensional network arranged to define aplurality of cellular spaces which intercommunicate with one another toform a continuous space phase. Material of this kind may be produced byspraying, dipping or electrodeposition of a metal on a polyurethane foammaterial. After deposition of the metal the polyurethane foam is removedby heating to ash-out the polyurethane. The polyurethane foam used is ofthe reticulated form, ie a foam in which the organic phase is athree-dimensional network with no substantial wall portions defining thecells, and the porous metallic material produced by the process outlinedabove has the property that it contains intercommunicating cells whichhave a capillary action and thus can act as a wick to conduct fluidthrough the material.

A particularly suitable material of the kind described above, having thecharacteristics of good durability at high temperatures, is the chromiumalloy foam produced by the methods described in the specifications ofcopending U.S. Pat. application Ser. No. 847,428 and Ser. No. 50,383.

In a fuel supply nozzle in accordance with the invention the porousmaterial described above may be in the form of a block or sheet havingholes pierced therethrough to form air passages linedfor at least partof their length with sheet metal, a backing plate being provided andsealed to the linings so as to enable air and fuel to be fed separatelyto the air passages and the porous material respectively. A number ofexamples of perforated structures of this kind are described in thecopending U.S. Pat. application Ser. No. 53,104.

One embodiment of the invention will now be described, by way ofexample, with reference to the accompanying drawing, which is adiagrammatic crosssectional side elevation of a gas turbine combustionchamber, showing a fuel supply nozzle, half in crosssection.

A combustion chamber 1 of a gas turbine engine is provided at the airinlet end 2 with a coaxially arranged fuel supply nozzle 3 of generallyconical, hollow form having a closed and rounded leading end comprisinga part-spherical cover member 4 formed from sheetmetal. The arrangementis such that combustion air flows axially through the combustion chamberl,

passing around the leading end 4 and the outside of the nozzle 3 andalso radially inwardly through apertures 5 in the sides of the nozzle.Fuel is fed, through means to be described, to mix the air passingradially through the apertures 5 so as to burn in the combustionchamber, dilution air passing around the outside of the nozzle and beingdeflected into the combustion zone by a deflector la.

The body of the nozzle is formed from a sheet-metal outer skin 6 ofhollow frusto-conical form which may be provided by spinning and whichis fitted around a correspondingly shaped skin 7 of porous metallicmaterial of the kind described above. The two skins are spaced from oneanother by means of dimples (not shown) formed in the outer sheet-metalskin 6 which form inwardly projecting areas to engage the inner skin 7.The inwardly projecting areas on the outer skin may engage correspondingoutwardly projecting areas on the inner skin to provide increasedspacing. Conveniently, as illustrated, the skin 7 of porous metallicmaterial may be strengthened by the provision of a metallic backingmember 7a which is suitably pierced to enable liquid or gaseous fluid topenetrate the skin 7.

Apertures 5 are formed by punching holes through the outer and innerskins 6 and 7 to constitute air supply passages sealed from the spacebetween the two skins, which space constitutes a fuel supply gallery 8.The sealing between the air supply passages 5 and the fuel supplygallery 8 is effected by punching the holes through the outer skin so asto deform the sheet-metal of the outer skin and carry it through to formlinings 9 for the holes in the form of tubular projections. The seal maybe improved by brazing. Fuel is supplied to the fuel supply gallery 8through fuel feed pipes 10,11 and 12.

In a turbine fuel supply nozzle of the kind described above arrangementscan be made for suitable distribution points for the fuel to be providedso that a reduction in turbine power and heat output can be achieved byshutting off the supply to various zones of the nozzle. For examplesheet metal segments 13 and 14 may be disposed between the apertures oftwo rings of apertures so as to divide axially the inner skin 7 and thegallery 8, and thereby form a plurality of separate fuel supply zonesserved by the pipes 10, 11 and 12 respectively. The zones furthest fromthe exit for hot gases, supplied through pipes 10 and 11 may be starvedof fuel to produce an initial reduction in power, and progressiveshutting down of fuel supplies may follow, leaving finally only a smallcontinuously burning ring near the exit.

A fuel supply nozzle as described above has an important advantage inthat it is suitable for use with a wide range of fuels, both liquid andgaseous.

Having now described my invention, whatl claim is:

l. A nozzle for supplying liquid or gaseous fuel to the combustionchamber of a gas turbine engine, comprising, an element formed from asheet of porous material having small pores through which fuel may flow,said element additionally having a surface area substantially throughoutwhich a plurality of passages are distributed, said passages beingsubstantially larger than said small pores, and said passages extendingthrough said element in a direction substantially perpendicular to thesurface of said element for supplying air through said element, and abacking member superimposed on said element in a spaced relationshipfrom said element to form a fuel supply gallery between said backing,

member and said element, said backing member formed with a plurality ofapertures therein corresponding to the plurality of passages in saidelement, the backing member material surrounding each aperture formed asa tubular projection extending into association with its correspondingpassage in the element.

2. A nozzle according to claim 1, in which the porous material ismetallic material of the kind in the form of a three-dimensional networkarranged to define a plurality of cellular spaces which intercommunicatewith one another to form a continuous space phase.

cording to claim 1. 7. A nozzle according to claim 1, wherein saidtubular projections extend into the corresponding passages of saidelement, in contact with said element.

* IF I! t

1. A nozzle for supplying liquid or gaseous fuel to the combustionchamber of a gas turbine engine, comprising, an element formed from asheet of porous material having small pores through which fuel may flow,said element additionally having a surface area substantially throughoutwhich a plurality of passages are distributed, said passages beingsubstantially larger than said small pores, and said passages extendingthrough said element in a direction substantially perpendicular to thesurface of said element for supplying air through said element, and abacking member superimposed on said element in a spaced relationshipfrom said element to form a fuel supply gallery between said backingmember and said element, said backing member formed with a plurality ofapertures therein corresponding to the plurality of passages in saidelement, the backing member material surrounding each aperture formed asa tubular projection extending into association with its correspondingpassage in the element.
 2. A nozzle according to claim 1, in which theporous material is metallic material of the kind in the form of athree-dimensional network arranged to define a plurality of cellularspaces which intercommunicate with one another to form a continuousspace phase.
 3. A nozzle according to claim 1 which is of a hollowconical form having the fuel supply gallery arranged external to theporous material.
 4. A nozzle according to claim 3 in which the leadingend of the nozzle is provided with a rounded cover member.
 5. A nozzleaccording to claim 1, said nozzle having a plurality of zones, each ofsaid zones having an independent fuel supply means.
 6. A gas turbineengine incorporating a nozzle according to claim
 1. 7. A nozzleaccording to claim 1, wherein said tubular projections extend into thecorresponding passages of said element, in contact with said element.